We have a Tesla charger at home.
It's not 100% clear what you mean by this. If you mean a Tesla Wall Connector, then I agree with others that adjusting the dip switch to lower its maximum amperage is likely to be the most reliable option, although it's an awkward one, especially if you want to switch back and forth seasonally.
If, OTOH, you're relying on the Tesla Mobile Connector that came with the car, you might consider installing a third-party EVSE. An EVSE equipped with
JuiceNet, such as most
JuiceBox EVSEs, and some
Clipper Creek and
Aerovironment EVSEs, can be programmed to provide less than their maximum possible outputs via a phone app or Web interface. I'm not certain, but I suspect that
ChargePoint,
OpenEVSE, and perhaps some others can be programmed in a similar way. Investing in such an EVSE might be worthwhile, especially if you can find one at a good price.
Another option might be to buy an "underpowered" (16A, 24A, or whatever you need) EVSE for this specific purpose. Installing it alongside a Tesla Wall Connector seems wasteful, but if you plan to buy another EV in the not-too-distant future, having two EVSEs might be worthwhile. If you're relying on a Tesla Mobile Connector, or a Wall Connector on a NEMA 14-50 outlet, then you could swap the EVSEs seasonally.
One more point: Depending on the nature of the peak demand charge, you might be able to get around it by charging at off-peak times, like late at night. You can set scheduled charging pretty easily in the Tesla's UI. This approach has the advantage that you'll be moving your electric demand for charging to off hours, when the demand on the grid is low, and thus reducing the demand on what are likely the most expensive and polluting power sources in your area, which are spun up during peak usage periods. (The fact that you've got solar panels is irrelevant, if they're grid-tied. They produce power whether or not you use it; when you don't use the power, it just goes to your neighbors and reduces their demand on more remote power sources. Thus, your choices about when to charge
do affect the demand on those remote sources, either directly or indirectly, even when you have grid-tied solar panels on your house.)